It says 'No signal' on my screen

[JeggyCopper]

I am having this old pc with P27G motherboad. Im trying to turn it back on. But then the monitor says 'No signal'. The cpu fan is running with the 90s dust.

I took out the ram and put it back. So does the cmos.

What's the problem? Please help me. :-[

 

[White271]

Try to use one ram stick at the time only to test.
As very common problem is that one of sticks can be faulty.